High‐Amylose Starches to Bridge the “Fiber Gap”: Development, Structure, and Nutritional Functionality

Abstract

Although high‐amylose starches are not a recent innovation, their popularity in recent years has been increasing due to their unique functional properties and enhanced nutritional values in food applications. While high‐amylose maize, barley, and potato are commercially available, high‐amylose variants of other main crops such as wheat and rice have once been developed more recently and will be available commercially in the near future. This review summarizes the development, structure, and nutritional functionality of high‐amylose starches developed and reported so far. The range of biotechnological strategies utilized are reviewed, as are the consequent effects on structural properties at different length scales, as well as sensory aspects of foods containing high‐amylose starch (HAS). This review identifies the molecular and microstructural features contributing to digestive enzyme resistance not only in native HAS but also in forms of relevance to food processing. During heat treatment, HAS tends to retain or form dense molecular structures that resist amylase degradation through the retention of the granular structure as well as helices (type‐2 resistant starch [RS]), reassociation of glucan chains (type‐3 RS), and formation of lipid–amylose complexes (type‐5 RS). The review also identifies opportunities for food manufacturers and consumers to incorporate HAS in food products and diets for better nutritional outcomes.

Effect of semolina pudding prepared fromstarch branching enzyme IIaandbmutant wheat on glycaemic responsein vitroandin vivo: a randomised controlled pilot study

“…The rate of self-association depends on chain-lengths, concentration and cooling rate; high amylose starches are more likely to form double helical structures which are thought to be resistant to α-amylase digestion. 12 Starch digestibility is also strongly influenced by the surrounding food matrix properties, which can hinder starch gelatinisation during processing conditions and/or limit starch exposure to digestive enzymes and fluids during gastrointestinal transit. [13][14][15] Another factor that may influence the digestibility of foods made from wheat semolina is the presence of non-starch polysaccharides (NSPs).…”

Characterization of Prata Banana (Musa AAB‐Prata) Starch: Native and Modified by Annealing

“…The resistance to enzymatic digestion is also afforded by the interactions between amylose and amylopectin which provide starch a regular arrangement in the crystalline region . Furthermore, the amylose–lipid complex is proposed as resistant starch type 5 . It was expected that the resistant starch content would increase with the increase in temperature in the hydrothermal treatment, since the most pronounced effect of annealing on the structural starch characteristics is obtained at temperatures immediately below its gelatinization temperature …”

Changes in kernel properties, in situ gelatinization, and physicochemical properties of waxy rice with inhibition of starch branching enzyme during cooking

“…Cereal kernels, especially rice kernels, are mainly used as foods in people's daily life. Starch, as a major component of cereal kernel, is mainly composed of glucose polymers: amylose and amylopectin (Li et al ., ). Starch in cooked cereal foods is easily digested to glucose in the digestive tract that cells directly utilise to produce energy for their metabolic function (Ordonio & Matsuoka, ).…”

“…The deficiency of soluble starch synthase IIIa (SSSIIIa), which elongates the non‐reducing ends of branch‐chains of amylopectin, in indica rice can simultaneously increase amylose and lipid contents in the kernels, resulting in very high RS content through forming amylose‐lipid complexes with high resistance to hydrolytic enzymes (Zhou et al ., ). In addition, starches with amylopectin long branch‐chains and B‐type crystallinity have high RS content (Li et al ., , ; Zhu et al ., ). The deficiency of starch branching enzyme (SBE), which creates the branches of amylopectin, in cereal crops can not only reduce amylopectin branching degree and elongate amylopectin branch‐chains, but also improve AC and form B‐type crystallinity in endosperm (Wang et al ., ; Xia et al ., ; Li et al ., ).…”

“…In addition, starches with amylopectin long branch‐chains and B‐type crystallinity have high RS content (Li et al ., , ; Zhu et al ., ). The deficiency of starch branching enzyme (SBE), which creates the branches of amylopectin, in cereal crops can not only reduce amylopectin branching degree and elongate amylopectin branch‐chains, but also improve AC and form B‐type crystallinity in endosperm (Wang et al ., ; Xia et al ., ; Li et al ., ). Therefore, the high‐amylose cereal crops with inhibition of SBE contain high RS content in their kernels and have potential health benefits (Regina et al ., , ; Zhu et al ., ).…”